Circuit interrupter



Feb. 5, 1946. R. c. DICKINSON 2,394,046

CIRCUIT INTERRUPTER Filed Dec. 10, 1942 2 Sheets-Sheet 2 jzy. 2.

j ATTGRNEY/ Patented Feb. 5, 1946 CIRCUIT INTERRUPTER Robert C. Dickinson, Wilkinsburg, Paz, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application December Ill, 1942, Serial No. 468,454

18 Claims.

This invention relates to circuit interrupters in general, and, more particularly, to mounting arrangements and operating mechanism therefor.

An object of my invention is to provide an improved circuit interrupter of the multiple break type and to provide improved operating means therefor.

A more specific object of my invention is to provide an improved operating mechanism to simultaneously actuate the interrupting means provided in two substantially independently mounted housings.

Another object of my invention is to provide an improved circuit interrupter of the liquid break type comprising a plurality, herein disclosed as two; housings of the liquid-poor type. In the circuit breaker art, there is a growing tendency to improvise circuit interrupters utilizing only a relatively small quantity of liquid. My invention is peculiarly adapted to circuit interrupters of this type and is herein disclosed as applied to a circuit interrupter comprising two porcelain clad housings, in each of which is an arc-extinguishing assemblage of the liquid-poor type.

Another object of my invention is to provide an improved circuit interrupter of the type comprising two substantially independent housings containing interrupting structures, and providing an improved operating means to simultaneously actuate the interrupting means provided in the two housings. Preferably the mechanism for actuating said operating means is external to the two housings and is disposed between them.

Another object of my invention is to provide improved operating means for simultaneously actuating two are extinguishing units.

A further object is to provide an improved circuit interrupter in which two movable contacts cooperate with two relatively stationary contacts to establish two interrupting arcs, the two movable contacts also cooperating with each other to produce substantially simultaneously a pressure generating are. In some instances it is desirable to establish the pressure generating arc prior to the establishment of the interrupting arcs, and I provide improved means for accomplishing this.

Further objects and advantages will readily become apparent upon areading of the following description taken in conjunction with the drawings in which:

Figure 1 is a side elevational view, partly in section, of a circuit interrupter embodying my improved invention;

Fig. 2 is an enlarged view in cross section of the are extinguishing assemblage in one of the housings shown in the interrupter of Fig. 1:

Fig. 3 is an enlarged side elevational view in section of a modified type .of arc extinguishing assemblage which may be used in place of the arc extinguishing assemblage of Fig. 2 in the circuit interrupter of Fig. 1;

Fig. 4 is a modification of my invention which may be applied to the arc extinguishing assemblage shown in Fig. 2; and

Fig. 5 is a fragmentary elevational view in cross section of a modified construction for the assemblage of Fig. 3. 5

Referring to the drawings and in particular to Fig. 1, the reference numeral I generally indicates an upstanding weather-proof housing, in this instance composed of porcelain, supported on a base 2. The base 2 supports a second weatherproof housing generally indicated by the reference numeral 3. Each of the housings l, 3 encloses an arc extinguishing assemblage generally indicated by the reference numeral 4 which is submerged in a suitable arc extinguishing liquid, in this instance oil. A conductor 5 electrically connects the arc extinguishing assemblages 4 inclosed in the housings l, 3. The electrical circuit through the interrupter comprises the terminal 6, then passes through the are extinguishing assemblage 4 to the conductor 5 and thence through the second housing 3 in a similar manner to' the terminal I.

- An insulating operating shaft 8 serves to actuate the two are extinguishing assemblages 4 during the opening and closing operations. An insulating operating rod 9 serves to rotate the insulating operating shaft 8 and is actuated by a suitable operating mechanism designated by the reference numeral 941.

Referring to Fig. 2, which is an enlarged elevational view in cross section of the arc extinguishing assemblage 4, it will be noted that the arc extinguishing assemblage 4 comprises two are extinguishing units generally designated by the reference numeral l0. Each arc extinguishing unit Ill comprises a tubular insulating casing H which supports a plurality of insulating washers l2, l3 which have different internal diameters and consequently form a corrugated arcing chamber H. A stationary contact l5 cooperates with a moving contact iii, the latter secured as by welding to a metallic plate I! which is rigidly secured to a metallic operating rod I8. An insulating rod i9 is guided by the metallic cap 20 and has disposed thereon insulating washers 2i.

22 to form a corrugated insulating piston gen erally designated by the reference numeral 23.

A partly open metallic housing 24 is threadedly secured to the two insulating casings H. A cam plate 25 is disposed in the metallic housing 24 and is rigidly secured to the one end of the insulating operating shaft 8. Two curved cam slots 26 are formed in the cam plate 25, and pins 21 secured to the inner ends of the operating rods l8 move in these curved cam slots 26 during the opening and closing operation of the arc extinguishing assemblage 4. A flexible conductor 28 electrically connects the opposed inner ends of the operating rods l8. Vents 28 are provided in the walls of the tubular insulating casings II as shown. The are extinguishing assemblage 4 is supported within the weather-proof housing (see Fig. 1) by a metallic support plate 38 The operation of the arc extinguishing assemblage 4 will now be explained. To open and close the circuit interrupter shown in Fig. l, the operating mechanism 9a is actuated, either in response to overload conditions or manually, to cause the longitudinal motion of the insulating operating rod 9. This longitudinal motion of the operating rod 9 causes rotation of the insulating operating shaft 8. The rotation of the shaft 8 causes cam plate 25 to rotate, which rotation causes pins 21 to move in the curved cam slots 26 to cause the insulating pistons 23 to move into and out of the arcing chambers l4 to effect the respective separation and engagement of the stationary contacts IS with the moving contacts l6. ing assemblage 4 is in the closed circuit position the electrical circuit therethrough comprises the metallic cap 20, stationary contact 5, moving contact l6, metallic plate l1, metallic operating rod I8, flexible conductor 28, lower metallic operating rod [8, lower metallic plate I7, lower movable contact l6, lower stationary contact l to lower metallic cap 20. The electrical circuit then passes through the metallic support plate 30 (see Fig. l) which is electrically connected to the conductor 5. The circuit then passes through the housing 3 to the other terminal I of the circuit interrupter in a like manner.

During the opening operation the cam plate 25 is rotated by the shaft 8 to cause the metallic operating rods I 8 to move toward each other and hence to move the insulating pistons 23 into the arc chambers H. The are drawn between the stationary contacts |5 and the moving contacts I5 is extinguished by the motion of the oil toward the stationary contact caused by the piston action of the insulating pistons 23. The cam plate 25 continues its rotation until the pistons 23 strike the bottom of the casings II as shown in Fig. 2. Patent 2,253,009, which issued August 19, 1941, to Benjamin P. Baker and which was assigned to the same assignee as of this application describes and broadly claims the structure of the arc extinguishing unit I0.

Instead of using the cam plate 25, I may use a metallic lever 3| as shown in Fig. 4, which has rigidly secured thereto pins 32 which move in slots 33 provided at the opposed inner ends of the metallic operating rods i8. It will readily be apparent that rotation of the shaft 8 will cause rotation of the metallic lever 3| to result in opening and closing motion of the operating rods l8.

In Fig. 3 I show a modified arc extinguishing assemblage 34 which may, if desired, be used in When the arc extinguishplace of the arc extinguishing assemblage 4 shown in Fig. l. The modified arc extinguishing assemblage 34 comprises two tubular insulating casings 35 threadedly secured to metallic caps 36 at one end and threadedly secured at their other ends to the metallic housing 31 which is completely closed. Vents 38 are provided in the metallic caps 36. A pair of movable contacts 39 cooperates with a pair of resiliently mounted stationary contacts 40 to establish two interrupting arcs. Flexible conductors 4| electrically connect the stationary contacts 40 to the metallic caps 36. A plurality of insulating washers 42, 43 having different internal diameters provide corrugated arcing chambers I4. Metallic operating members 44 which are preferably integrally formed with the movable contacts 38 contain a pair of pressure generating contacts 45, 46 at their opposed inner ends. An insulating lever 41 rigidly fixed to the insulating shaft 8 and arranged for rotation is pivotally connected to the operating members 44 at 48. Guide links 49 pivoted at 50 to the inner wall of the housing 31 and also pivoted at 5| to the operating members 44 serve to guide the longitudinal motion of the operating members 44.

Substantially a straight line motion of the operating members 44 takes place. The length of the guide links 49 with respect to the length of the insulating lever 41 determines to what extent the motion of the operating members 44 will be straight line motion. It is to be understood, however, that the members 44 could be guided by fixed guides and a slot provided at the pivots 48 to result in a pure straight line motion of the operating members 44 in a manner similar to that shown in Fig. 4. Obviously, other arrangements could be provided to cause a straight line motion of the operating members The operation of the arc extinguishing assemblage 34 will now be explained. In the closed circuit position of the assemblage as shown in Fig. 3, the electrical circuit therethrough comprises the metallic cap 36, flexible conductor 4|, stationary contact 40, movable contact 39, operating member 44, contact 46, contact 45, lower operating member 44, lower stationary contact 40, flexible conductor 4| to lower cap member 36. As explained previously the arc extinguishing assemblage 34 may be used in Fig. 1 in place of the arc extinguishing assemblage 4 there shown. In the opening operation the shaft 8 is rotated in a clockwise direction to cause a clockwise rotation of the insulating lever 41. This substantially simultaneously produces a pressure generating are between the contacts 45, 46 and two interrupting arcs formed between the contacts 40 and the movable contacts 38. The oil disposed in the closed housing 31 is put under pressure by the pressure generating arc and is forced in opposite directions through the arcing chambers l4 and out through the vents 38 in the caps 36 to effect a rapid extinction of the two interrupting arcs.

In certain applications it is desirable to establish the pressure generating are a predetermined time before the establishment of the interrupting arcs. Fig. 5 shows a slight change in construction of the arc extinguishing assemblage 34 in Fig. 3 which will provide the establishment of the pressure generating are at a predetermined time before the establishment of the interrupting arcs. Referring to Fig. 5, it will be noted that the metallic cap 36 has a central vent 52. A

metallic bellows I! rigidly secured as'by welding to the metallic cap 38 serves to resiliently mount, by means of the compression spring 54, a stationary contact I! having a central vent 51 therethrough. A movable contact 88, which is analogous to the movable contact 89 in Fig. 3, engages the stationary contact 55, as shown. substantially closing the aperture 51 through the stationary contact 55 in the closed circuit position. During the opening operation the stationary contact follows the initial movement of the movable contact 56 until the stationary contact 55 strikes the insulating washer 42 at which time the movable contact 58 separates from the stationary contact 55. It will, consequently, be seen that the interrupting are formed between the movable contact 58 and the stationary contact 55 will be established at a predetermined time after the establishment of the pressure generating are between the contacts 45, 46 (see Fig. 3). This construction of forming the pressure generating arc prior to the establishment of the two interrupting arcs produces an increased pressure within the housing 31 which is suddenly released when the moving contacts 56 separate from the stationary contacts 55. When this occurs oil will be forced under pressure through the arcing chambers l4 and through the central apertures 51 in the stationary contacts 55, through the bellows 53 and out through the central vents 52. This flow of fluid quickly extinguishes the interrupting arcs formed between the stationary contacts 55 and the moving contacts 56.

It will be observed that with the construction shown in Fig. 3 no flexible shunts are required. 3

Since the operating members 44 are integrally formed with the moving contacts 39 a current path through a solid conductor is thereby formed. The operating mechanism 9a may, by suitable means well known in the art, produce the necessary resilient contact pressure. It will also be noted that by the simple rotation of the shaft 8 substantial formation of the pressure generating arc with a pair of interrupting arcs may be effected. By'a slight change in construction as shown in Fig. 5 the pressure generating arc may be formed at a predetermined time prior to the establishment of the interrupting arcs.

Certain features of the arcing chamber It in Fig. 3 are described and claimed in a patent application filed May 15, 1940, Serial No. 335,248, by

Benjamin P. Baker, now Patent 2,304,529 which issued December 8, 1942, and which was assigned to the assignee of the instant application.

It will be apparent that my improved operating mechanism provides a simple and eflective means for simultaneously operating a plurality of arc extinguishing units, and which is readily adaptable to a construction whereby two arc extinguishing assemblages are independently mounted. The operating mechanism is particularly suitable for high voltage application. Although I have shown certain embodiments of my invention as used in a liquid type circuit interrupter, it is to be understood that other are extinguishing fluids, such as air or other gases, may be used in place of the liquid. If air were used the washers l2, IS in Fig. 2 and the washers 42, 43 in Figs. 3 and 5 would be preferably made out of a gas evolving material.

Although I have shown and described certain structures, it is to be understood that the same were merely for purposes of illustration and that changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. In a circuit interrupter, a pair of relatively stationary contacts, a pair of movable contacts cooperating at one end with said stationary contacts to form two interrupting arcs, the other ends of said pair of movable contacts cooperating to establish a pressure generating are.

2. In a circuit interrupter, a pair of relatively stationary contacts, a pair of relatively movable contacts cooperating at one end with said stationary contacts to establish a pair of interrupting arcs, the otherends of said pair of movable contacts cooperating to establish a pressure generating arc, and rotatable operating means for actuating said pair of relatively movable contacts.

3. In' a circuit interrupter, a pair of relatively stationary contacts, a pair of relatively movable contacts cooperating at one end with said stationary contacts to establish a pair of interrupting arcs, the other ends of said pair of movable contacts cooperating to establish a pressure generating arc, and means for delaying the formation of said interrupting arcs until a predetermined time after the formation of said pressure generating are.

4. In a circuit interrupter, a pair of stationary contacts, a pair of movable contacts cooperable with said pair of stationary contacts to establish a pair of interrupting arcs, said pair of movable contacts also cooperating with each other to establish a pressure generating are.

5. In a circuit interrupter, a pair of stationary contacts cooperable with a pair of moving contacts to establish a pair of interrupting arcs, said pair of moving contacts being cooperable with each other to establish a pressure generating are a predetermined time before the time of establishment of said pair of interrupting arcs.

6. In a circuit interrupter, a stationary contact with an aperture therethrough, a movable contact engaging said stationary contact adjacent the position of said aperture, and a bellows assisting to support said stationary contact in a resilient manner.

7. In a circuit interrupter, a pair of stationary contacts, a pair of moving contacts cooperable with said pair of stationary contacts to establish a pair of interrupting arcs, said pair 01' moving contacts also cooperating with each other to establish a pressure generating arc, and rotatable lever means for actuating said movable contacts in opposite directions.

8. In a circuit interrupter. a pair of stationary contacts cooperating with a pair of movable contacts to establish a pair of interrupting arcs, said pair of movable contacts cooperable with each other to establish a pressure generating arc a predetermined time before the establishment of said pair of interrupting arcs, and rotatable lever means for actuating said pair of movable contacts in opposite directions.

9. In a liquid circuit interrupter, a plurality of independently mounted housings each of the liquid-poor type, terminal means disposed at the top of each housing, interconnecting means disposed at the bottom of the housings electrically interconnecting the two housings in series relation, and rotatable operating means interconnecting the two housings intermediate the ends thereof.

10. In a liquid break circuitinterrupter, two porcelain-clad arc-extinguishing assemblages each being of the liquid-poor type. terminal means disposed at the top of each assemblage, interconnecting means disposed at the bottom of the assemblages electrically interconnecting the two assemblages in series relation, and rotatable operating means extending between the assemblages to simultaneously cause the actuation thereof.

11. In a liquid break circuit interrupter, two independently mounted porcelain housings each enclosing an arc-extinguishing assemblage of the liquid-poor type, each assemblage including two vertically disposed serially related arc extinguishing units, terminal means disposed at the top of each assemblage, means electrically interconnecting the two housings in series relation and disposed at the lower ends of the two assemblages, and rotatable operating means connected at its ends between the two units of each assemblage for mechanically operating the two assemblages simultaneously.

12. In a liquid break circuit interrupter, a pair of parallel vertically disposed independently mounted housings, arc extinguishing means of the liquid-poor type within each housing, terminal means disposed at the top of each housing, interconnecting means disposed at the bottom of the housings electrically interconnecting the arc extinguishing means in the two housings in series relation, and rotatable operating means for the arc extinguishing means interconnecting the two housing intermediate the ends thereof.

13. In a circuit interrupter, a pair of parallel vertically disposed porcelains, each porcelain containing an arc extinguishing assemblage, a line terminal disposed at the top of each porcelain, interconnecting means extending between the two porcelains adjacent the lower ends of the arc extinguishing assemblages for electrically interconnecting them in series relation, and rotatable means extending between the two porcelains for operating the arc extinguishing assemblages within the porcelains,

14. In a circuit interrupter, a pair of parallel vertically disposed porcelains, an arc extinguishing assemblage within each porcelain, each assemblage including two vertically disposed arc extinguishing units serially related, a line terminal disposed at the top of each porcelain, interconnecting means extending between the two porcelains adjacent the lower ends of the are extinguishing assemblages for electrically interconnecting them in series relation, and rotatable means extending between the two porcelains for operating the arc extinguishing assemblages within the porcelains.

15. In a circuit interrupter, a pair of parallel vertically disposed porcelains, an arc extinguishing assemblage within each porcelain, each assemblage including two vertically disposed arc extinguishing units serially related, a line terminal disposed at the top of each porcelain, interconnecting means extending between the two porcelains adjacent the lower ends of the arc extinguishing assemblages for electrically interconnecting them in series relation, and rotatable means extending between the two porcelains for operating the arc extinguishing assemblages within the porcelains, the rotatable means connected at its ends between the two units in each assemblage.

16. In a circuit interrupter, a plurality of independently mounted housings, arc extinguishing means of the liquid-poor type within each housing, terminal means disposed at the top of each housing, interconnecting means disposed at the bottom of the housings electrically interconnecting the arc extinguishing means in the two housings in series relation, rotatable operatingmeans for the arc extinguishing means interconnecting the two housings intermediate the ends thereof, and a supporting insulating mounting for each housing disposed between ground and the interconnecting means.

17. In a circuit interrupter, two porcelain-clad arc-extinguishing assemblages, terminal means disposed at the top of each assemblage, interconnecting means disposed at the bottom of the assemblages electrically interconnecting the two assemblages in series relation, rotatable operating means extending between the assemblages to simultaneously cause the actuation thereof, and a supporting insulating mounting for each housing disposed between ground and the interconnecting means.

18. In a circuit interrupter, two independently mounted housings, a line terminal disposed at the top of each housing, a supporting portion adiacent the lower end of each housing, an arc extinguishing assemblage within each housing, interconnecting means electrically interconnecting the two assemblages and terminating at the two housings adjacent the top of the supporting portions and also adjacent the lower ends of the two are extinguishing assemblages, and rotatable operating means interconnecting the two housings intermediate the ends thereof.

ROBERT C. DICKINSON. 

